Re: Make meta-ti comply with Yocto Project BSP requirements

[Tomas Frydrych <tf+lists.yocto@r-finger.com>]

On 14/09/12 12:29, Richard Purdie wrote:
> On Fri, 2012-09-14 at 11:26 +0100, Tomas Frydrych wrote:
>> On 14/09/12 09:08, Denys Dmytriyenko wrote:
>>> 3. Inheriting (i.e. inherit systemd) classes from another layer, such as 
>>> meta-systemd. This behavior breaks parsing and requires BBMASK-ing those 
>>> problematic recipes. Although, it requires an "application" layer and not a 
>>> "distribution" one, it's quite bad nonetheless, as it breaks parsing. High 
>>> priority.
>>
>> I am not sure about this one; it is reasonable / necessary for a bsp
>> layer to provide an -initd / -systemd packages (e.g., the pvr drivers
>> need this, the gstreamer-ti package needs this), and as long as there is
>> no systemd.bbclass in oe-core, I suspect the only answer is to split the
>> bsp layer into -bsp, -bsp-initd and --bsp-systemd. I am not sure whether
>> such endless proliferation of layers is a particularly good solution?
> 
> I don't think PVR modules having a dependency on some particular init
> system is a good thing.
> 
> What we need is a good core init system architecture and then these
> pieces can plug into that in whatever way is appropriate.

You could have a single bbclass that would provide the necessary
functionality for both systems; the current two classes could just be
aliases for it, providing backward compatibility. That would make the
basic problem of having more than one init bbclass go away.

> 
> I appreciate we're not there yet however I think the overall goal of
> separating hardware support from "policy" is a good one. 

Yes, but we are not talking about having policy in the bsp layer, we are
talking about the bsp layer supporting common policy types that a higher
layer can choose to impose. I think the distinction between 'policy' and
'policy awareness' is an important one.

> There are a few
> pain points we need to work through but if it was easy, we'd already
> have done it :)
> 
> systemd support in OE-Core is being deferred to 1.4 as I want it done
> well and would be too rushed given where we're at in the schedule now.

Actually, there is a really simple fix for this specific problem, and
that's for oe-core to include a dummy systemd.bbclass that does nothing.
This stops the parsing from being broken, and it makes no difference if
you are including meta-systemd.

Tomas